Liquid crystal display apparatus and method of forming the same

ABSTRACT

A liquid crystal display device including a first substrate, a common electrode formed over the first substrate, and a second substrate disposed opposite the first substrate. A common voltage-applying member applies a common voltage to the common electrode and maintains a cell gap between the first substrate and the second substrate. The common voltage-applying member includes an insulator and a conductor formed over the insulator.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority based on Korean Patent Application No.2003-30790 filed on May 15, 2003.

BACKGROUND

1. Technical Field

The present disclosure relates to a liquid crystal display (LCD)apparatus, and more particularly to an LCD apparatus manufactured by asimplified process and at low cost.

2. Description of the Related Art

A conventional LCD apparatus displays an image using liquid crystal. Inorder to display the image, the conventional LCD apparatus includes anLCD panel and a backlight assembly for supplying light to the LCD panel.The LCD panel includes a first substrate, a second substrate and liquidcrystal interposed between the first and second substrates.

The first substrate includes a plurality of first electrodes and thesecond substrate includes a second electrode facing the firstelectrodes. Each of the first electrodes receives a pixel voltagedifferent from each other and the second electrode receives a commonvoltage having a uniform voltage level. The arrangement of the liquidcrystal is varied according to an electric field applied between thefirst and second electrodes.

The pixel voltage and common voltage are applied to the first substrate.The pixel voltage is applied to the first electrodes and the commonvoltage applied to the first substrate is provided to the secondsubstrate through a conductive spacer that is electrically connectedbetween the first and second substrates. The conventional conductivespacer is typically formed of gold (Au) and is formed at many locationsof the first substrate.

In a manufacturing processes for an LCD apparatus in which a commonvoltage from a first substrate is applied to a second substrate througha conductive spacer, much time is required to form the conductivespacer. For example, in a conventional manufacturing process, a commonelectrode and color filters are formed over a substrate of an LCD panel,and separate manufacturing steps are required to form the conductivespacer over the color filters and the common electrode. These additionalmanufacturing steps increase manufacturing time of the conventional LCDapparatus and require more raw materials. Also, because the conventionalconductive spacer is made of gold (Au), manufacturing cost for the LCDapparatus may be high.

SUMMARY OF THE INVENTION

According to various exemplary embodiments of the present invention, acommon voltage applied to a first substrate of an LCD apparatus isprovided to a common electrode formed over a second substrate through aconductor formed over an insulator. Thus, the manufacturing processesfor the LCD apparatus may be simplified and the manufacturing cost forthe LCD apparatus may be reduced.

A liquid crystal display device according to an embodiment of theinvention includes a first substrate,a common electrode formed over thefirst substrate, and a second substrate disposed opposite the firstsubstrate. A common voltage-applying member applies a common voltage tothe common electrode and maintains a cell gap between the firstsubstrate and the second substrate. The common voltage-applying memberincludes an insulator and a conductor formed over the insulator.

In at least one embodiment of the invention, a color filter is formedover one of the first and second substrates. The color filter and theinsulator are formed simultaneously and of the same material.

In at least one embodiment of the invention, the common electrode andthe conductor are formed simultaneously and of the same material.

In at least one embodiment of the invention, a plurality of pixelelectrodes are formed over the second substrate, and the plurality ofpixel electrodes and the conductor are formed simultaneously and of thesame material.

A method of forming a liquid crystal display device according to anembodiment of the invention includes forming a common electrode over afirst substrate, disposing a second substrate opposite the firstsubstrate, forming an insulator over one of the first substrate and thesecond substrate, and forming a conductor over the insulator. Theinsulator and the conductor form a common voltage-applying member thatapplies a common voltage to the common electrode and that maintains acell gap between the first substrate and the second substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become readily apparent by describingpreferred embodiments thereof in detail with reference to theaccompanying drawings wherein:

FIG. 1 is a schematic view of an LCD apparatus according to an exemplaryembodiment of the present invention;

FIG. 2 is a schematic plan view of an LCD apparatus according to ananother exemplary embodiment of the present invention;

FIG. 3 is a partially enlarged view showing a portion “A” of FIG. 2;

FIG. 4 is a partially enlarged view showing a portion “B” of FIG. 2;

FIG. 5 is a cross-sectional view taken along the line V-V′ of FIG. 2;

FIGS. 6A and 6B are schematic views showing a gate bus line and a gateelectrode formed on the first transparent substrate according to anexemplary embodiment of the present invention;

FIGS. 7A and 7B are schematic views showing a channel layer formed on afirst transparent substrate according to an exemplary embodiment of thepresent invention;

FIGS. 8A and 8B are schematic views showing a pixel electrode formed ona first transparent substrate according to an exemplary embodiment ofthe present invention;

FIGS. 9A and 9B are schematic views showing a black matrix formed on asecond transparent substrate according to an exemplary embodiment of thepresent invention;

FIGS. 10A and 10B are schematic views showing a red color filter and acolor filter layer formed on a second transparent substrate according toan exemplary embodiment of the present invention;

FIGS. 11A and 11B are schematic views showing a green color filter and agreen color filter layer formed on a second transparent substrateaccording to an exemplary embodiment of the present invention;

FIGS. 12A and 12B are schematic views showing a blue color filter and ablue color filter layer formed on a second transparent substrateaccording to an exemplary embodiment of the present invention;

FIG. 13 is a cross-sectional view showing a common electrode and aconductor formed on a second transparent substrate according to anexemplary embodiment of the present invention;

FIG. 14 is a cross-sectional view of an LCD according to anotherexemplary embodiment of the present invention;

FIG. 15 is a cross-sectional view of an LCD according to anotherexemplary embodiment of the present invention;

FIG. 16 is a cross-sectional view of an LCD apparatus according toanother exemplary embodiment of the present invention;

FIG. 17 is a cross-sectional view of an LCD apparatus according toanother exemplary embodiment of the present invention;

FIG. 18 is a cross-sectional view of an LCD apparatus according toanother exemplary embodiment of the present invention;

FIG. 19 is a cross-sectional view of an LCD apparatus according toanother exemplary embodiment of the present invention;

FIG. 20 is a cross-sectional view of an LCD apparatus according toanother exemplary embodiment of the present invention; and

FIG. 21 is a cross-sectional view of an LCD apparatus according toanother exemplary embodiment of the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 is a schematic view showing an LCD apparatus according to anexemplary embodiment of the present invention.

Referring to FIG. 1, an LCD apparatus 600 according to the presentembodiment of the invention includes a first substrate 100, a secondsubstrate 200, a common voltage-applying member 300 and liquid crystal400. The first substrate 100 faces the second substrate 200, and thecommon voltage-applying member 300 and the liquid crystal 400 aredisposed between the first and second substrates 100 and 200.

The first substrate 100 includes a first transparent substrate 110 and aplurality of pixels 120 on the first transparent substrate 110. Thepixels 120 are formed on a first display area DA1 of the first substrate110 in a matrix configuration, and the first display area DA1 issurrounded by a first peripheral area PA1. Each of the pixels 120includes a pixel electrode 129 to which a pixel voltage is applied. Thefirst transparent substrate 110 includes a pixel voltage applying linefor applying a pixel voltage from the first peripheral area PA1 to thefirst display area DA1 and a common voltage applying line 190 forapplying a common voltage to the first peripheral area PA1.

The second substrate 200 includes a second transparent substrate 210 anda common electrode 220 formed on the second transparent substrate. Thesecond substrate 200 includes a second display area DA2 facing the firstdisplay area DA1 of the first substrate 100 and a second peripheral areaPA2 surrounding the second display area DA2. The common electrode 220 isformed at the second display area DA2 and second peripheral area PA2 soas to partially cover the second display area DA2 and second peripheralarea PA2. The common electrode 220 receives the common voltage appliedto the common voltage applying line 190 of the first substrate 100.

The first and second substrates 100 and 200 are disposed such that thepixel electrodes 120 face the common electrode 220.

The common voltage-applying member 300 is disposed between the first andsecond substrates 100 and 200 and applies the common voltage applied tothe first peripheral area PA1 of the first substrate 100 to the commonelectrode 220 of the second substrate 200. The common voltage-applyingmember 300 is disposed between the first peripheral area PA1 of thefirst substrate 100 and the second peripheral area PA2 of the secondsubstrate 200. In various exemplary embodiments of the invention, thecommon voltage-applying member 300 may be formed at the first peripheralarea PA1 or the second peripheral area PA2. The common voltage-applyingmember 300 includes an insulator 350 and a conductor 390 wrapping theinsulator 350. The insulator 350 includes a photosensitive material andis formed during fabrication of the first and second substrates 100 and200. The conductor 390 is formed on a surface of the insulator 350during formation of the common electrode 220 or the pixel electrode 129.

The liquid crystal 400 is disposed between the pixels 120 of the firstsubstrate 100 and the common electrode 220 of the second substrate 200.The liquid crystal 400 has a varying arrangement due to an electricfield difference between the pixel voltage applied to the pixelelectrode 129 of the first substrate 100 and the common voltage appliedto the common electrode 220 through the common voltage applying member300.

The LCD apparatus 600 according to the present embodiment of theinvention may be manufactured to have a structure that can apply thecommon voltage applied to the first substrate 100 to the secondsubstrate 200 without any additional process steps. Thus, themanufacturing processes for the LCD apparatus 600 may be simplified.Also, the LCD apparatus 600 may be manufactured at a lower cost becauseit does not use a spacer made of gold (Au).

FIG. 2 is a schematic plan view showing an LCD apparatus according toanother exemplary embodiment of the present invention. FIG. 3 is apartially enlarged view showing a portion “A” of FIG. 2. FIG. 4 is apartially enlarged view showing a portion “B” of FIG. 2. FIG. 5 is across-sectional view taken along the line V-V′ of FIG. 2.

Referring to FIG. 2, an LCD apparatus 600 includes a first substrate100, a second substrate 200, a power supply member 300 and liquidcrystal 400.

Referring to FIG. 5, the first substrate 100 includes a firsttransparent substrate 110 having a first display area DA1 and a firstperipheral area PA1 surrounding the first display area DA1 and aplurality of pixels 120 disposed at the first display area DA1.

Referring to FIG. 3, the pixels 120 are arranged at the first displayarea DA1 in a matrix configuration. For example, when the LCD apparatus600 has a resolution of 1024×768, 1024×768×3 units of the pixels 120units are formed at the first transparent substrate 110.

Each of the pixels 120 includes a gate bus line 121, a data bus line122, a thin film transistor (TFT) 128 and a pixel electrode 129.

Referring to FIGS. 2 and 3, the gate bus line 121 is extended in a firstdirection D1 from the first peripheral area PA1 through the firstdisplay area DA1. If the LCD apparatus 600 has a resolution of 1024×768,768 gate bus lines 121 are formed at the first transparent substrate110. The 768 gate bus lines 121 are divided into three groups and eachgroup is disposed at the first peripheral area PA1 as a gate bus linechannel 121 a. Thus, three gate bus line channels 121 a are formed atthe first peripheral area PA1. Each of the gate bus line channels 121 ais connected to a gate tape carrier package (TCP) to which a drivingsignal is applied.

The data bus line 122 is insulated from the gate bus line 121 andextended in a second direction D2 substantially perpendicular to thefirst direction D1. The data bus line 122 is extended from the firstperipheral area PA1 to the first display area DA1. If the LCD apparatus600 has a resolution of 1024×768, 1024×3 units of data bus lines 122 areformed at the first transparent substrate 110. The 1024×3 units of databus lines 122 are divided into twelve groups and each group is disposedat the first peripheral area PA1 as a data bus line channel 122 a. Thus,twelve data bus line channels 122 a are formed at the first peripheralarea PA1. Each of the data bus line channels 122 a is connected to adata TCP to which a driving signal is applied.

Referring to FIG. 3, the TFT 128 includes a gate electrode G, a sourceelectrode S, a drain electrode D and a channel layer C. The gate andsource electrodes G and S are extended from the gate and data bus lines121 and 122, respectively. The channel layer C is insulated from thegate electrode G and disposed on the gate electrode G. When a voltage isapplied to the gate electrode G, the channel layer C operates as aconductor. When the voltage is not applied to the gate electrode G, thechannel layer C operates as an insulator. The source and drainelectrodes S and D are electrically insulated from the channel layer Cand connected to the channel layer C.

The pixel electrode 129 is connected to the drain electrode D of the TFT128. The pixel electrode 129 comprises a transparent conductivematerial, such as, for example, indium fin oxide, indium zinc oxide,etc.

Referring to FIG. 4, a common voltage applying line 123 is formed at aposition adjacent to the data bus line channel 122 a of the firstperipheral area PA1 of the first substrate 100. The common voltageapplying line 123 receives the common voltage externally providedthrough the first peripheral area PA1 of the first substrate 100. Aplurality of common voltage applying lines is formed at the firstperipheral area PA1 so as to apply the common voltage having a uniformlevel to the common electrode 220 shown in FIG. 5.

Referring to FIGS. 2 and 5, the second substrate 200 includes a secondtransparent substrate 210, a color filter 230, a common electrode 220and a power-applying member 300. The second substrate 200 may furtherinclude a black matrix 240.

The second transparent substrate 210 faces the first transparentsubstrate 110 and includes a second display area DA2 and a secondperipheral area PA2 surrounding the second display area DA2. The seconddisplay area DA2 and second peripheral area PA2 face the first displayarea DA1 and first peripheral area PA1 of the first substrate 100,respectively.

The color filter 230 is disposed at the second display area DA2 of thesecond transparent substrate 210 in a matrix configuration, therebyfacing the pixel electrode 129. The color filter 230 includes a redcolor filter 232, a green color filter 234 and a blue color filter 236.Two color filters adjacent to each other among the red, green and bluecolor filters 232, 234 and 236 may be overlapped at edges thereof. Thus,the red, green and blue color filters 232, 234 and 236 may prevent lightfrom leaking between the red, green and blue color filters 232, 234 and236.

In the present exemplary embodiment of the invention, the black matrix240 is formed between the first transparent substrate 210 and commonelectrode 220. The black matrix 240 has a lattice-shape so as to block aspace between the pixel electrode 129 and an adjacent pixel electrode.The black matrix 240 preferably includes a chromium layer, adouble-layer having a chromium layer and a chromium oxide layer, or ablack organic layer having a light transmittance substantially equal tothat of chromium Cr.

The common electrode 220 includes a transparent conductive material,such as, for example, ITO, IZO or the like. The common electrode 220 isformed over the second display area DA2 and on a portion of the secondperipheral area PA2 so as to cover the color filter 230.

Referring to FIG. 5, the power-applying member 300 includes an insulator310 and a conductor 220 a.

The insulator 310 is formed at the second peripheral area PA2 of thesecond substrate 200. The insulator 310 faces the common voltageapplying line 123 formed at the first peripheral area PA1 of the firstsubstrate 100. In the present exemplary embodiment of the invention, theinsulator 310 is formed using portions of color filter layers used forthe color filter 230. The color filter layers include a red color filterlayer 232 a, a green color filter layer 234 a and a blue color filterlayer 236 a. The red, green and blue color filter layers 232 a, 234 aand 236 a formed at the second peripheral area PA2 are formed at thesame time the color filter 230 is formed at the second display area DA2.Particularly, the red color filter layer 232 a is formed with the redcolor filter 232 formed at the second display area DA2, the green colorfilter layer 234 a is formed on the red color filter layer 232 a withthe green color filter 234 formed at the second display area DA2, andthe blue color filter layer 236 a is formed on the green color filterlayer 234 a with the blue color filter 236 formed at the second displayarea DA2.

The insulator 310 having the red, green and blue color filter layers 232a, 234 a and 236 a has a thickness substantially equal to a distancebetween the first and second substrates 100 and 200.

The conductor 220 a covers the insulator 310 formed at the secondperipheral area PA2. The conductor 220 a is partially connected to thecommon electrode 220 and common voltage applying line 123. In thepresent exemplary embodiment of the invention, the conductor 220 aincludes a transparent conductive material, such as, for example, ITO orIZO. The conductor 220 a may be formed using the same material as thecommon electrode 220, so that the conductor 220 a may be simultaneouslyformed with the common electrode 220.

A sealing member 410 having a band shape is formed at a boundary betweenthe first peripheral area PA1 and first display area DA1 of the firstsubstrate 100 or at a boundary between the second peripheral area PA2and second display area DA2 of the second substrate 200. The liquidcrystal 400 is dropped into the first display area DA1 or second displayarea DA2 surrounded by the sealing member 410, and then the firstsubstrate 100 is assembled with the second substrate 200. Alternatively,the liquid crystal 400 may be injected between the first and secondsubstrates 100 and 200 after the first and second substrates 100 and 200are assembled with each other using the sealing member 410.

FIGS. 6A-13 are cross sectional views showing steps of a method forforming a liquid crystal display apparatus according to an embodiment ofthe invention. Referring to FIGS. 6A and 6B, a gate metal, such as, forexample, aluminum, aluminum alloy, etc., is formed over the firsttransparent substrate 110 of the first substrate 100 using chemicalvapor deposition or sputtering.

A photoresist layer is formed on the first transparent substrate 110 andthe photoresist layer is partially exposed to light using a first mask.As a result, the gate bus line 121 is formed on the first transparentsubstrate 110 in the first direction D1 and the gate electrode Gextending from the gate bus line 121 in the second direction D2 isformed as shown in FIGS. 2 and 6B. When the LCD apparatus 600 has aresolution of 1024×768, 768 gate bus lines 121 are formed on the firsttransparent substrate 110 and 1024×3 units of gate electrodes G extendfrom one gate bus line 121.

After the gate bus line 121 and gate electrode G are formed on the firsttransparent substrate 110, a gate-insulating layer 127 is formed overthe first transparent substrate 110.

Referring to FIGS. 7A and 7B, an amorphous silicon layer, an n⁺amorphous silicon layer and a source/drain metal layer are successivelyformed on the gate-insulating layer 127. A photoresist layer is formedon the source/drain metal layer and patterned using a second mask,thereby forming a photoresist pattern at a position corresponding to thechannel layer C. The source/drain metal layer, n⁺ amorphous siliconlayer and amorphous silicon layer are successively etched using thephotoresist pattern as a mask. As a result, the data bus line 122extended in the second direction D2, source electrode S extended fromthe data bus line 122 in the first direction D1 and drain electrode Dextended from the data bus line 122 in the first direction D1 aresimultaneously formed. When the photoresist pattern is etched back, then⁺ amorphous silicon layer is divided to form the channel layer C.

Referring to FIGS. 8A and 8B, a transparent protection layer 128 isformed over the first transparent substrate 110 and a photoresist layeris formed on the protection layer 128. A contact hole is formed in theprotection layer 128 to partially expose the drain electrode D byetching the protection layer 128 using a third mask. A transparentconductive material, such as, for example, ITO or IZO, is formed overthe protection layer 128. The pixel electrode 129 is formed bypatterning the transparent conductive material using a fourth mask.

Referring to FIGS. 9A and 9B, a black layer, such as, for example, achromium layer, a double-layer having a chromium layer and a chromiumoxide layer or a black organic layer, is formed over the secondtransparent substrate 210. A photoresist layer is coated on the blacklayer and patterned, and the patterned photoresist layer is used to forman opening 242 in the black layer corresponding to the pixel electrode129 of the first substrate 100. As a result, the black matrix 240 isformed at the second display area DA2 of the second transparentsubstrate 210 as shown in FIG. 9B.

Referring to FIGS. 10A and 10B, a red color filter material is formedover the second transparent substrate 210. The red color filter materialis patterned through a photolithography process to form the red colorfilter layer 232 a at the second peripheral area PA2 and to form the redcolor filter 232 at the opening 242 of the black matrix 240.

Referring to FIGS. 11A and 11B, a green color filter material is formedover the second transparent substrate 210. The green color filtermaterial is patterned through a photolithography process to form thegreen color filter layer 234 a on the red color filter layer 232 aformed at the second peripheral area PA2 and to form the green colorfilter 234 at the opening 242 of the black matrix 240.

Referring to FIGS. 12A and 12B, a blue color filter material is formedover the second transparent substrate 210. The blue color filtermaterial is patterned through a photolithography process to form theblue color filter layer 236 a on the green color filter layer 234 aformed at the second peripheral area PA2 and to form the blue colorfilter 236 at the opening 242 of the black matrix 240.

The red, green and blue color filter layers 232 a, 234 a and 236 aformed at the second peripheral area PA2 of the second transparentsubstrate 210 operate as the insulator 310. As shown in FIGS. 12 a and12 b, the insulator 310 has a nub-like shape having a base portionformed of the red color filter layer 232 a and a top portion formed ofthe blue color filter layer 236 a. The red color filter layer 232 a haslarger cross sectional area than that of the blue color filter 236 a, sothat the insulator 310 is tapered from the base portion to the topportion.

Referring to FIG. 13, a transparent conductive layer, such as, forexample, ITO or IZO, is formed over the second transparent substrate 210to cover the red, green and blue color filters 232, 234 and 236. Thetransparent conductive layer may be formed only at the second displayarea DA2 of the second transparent substrate 210, or formed to cover theinsulator 310 formed at the second peripheral area PA2 and the colorfilter 230 formed at the second display area DA2 of the secondtransparent substrate 210.

In present exemplary embodiment of the invention, the transparentconductive layer covers the insulator 310 formed at the secondperipheral area PA2 and the color filter 230 formed at the seconddisplay area DA2 of the second transparent substrate 210. A portion ofthe transparent conductive layer, which covers the color filter 230 ofthe second display area DA2, operates as the common electrode 220, and aportion of the transparent conductive layer, which covers the insulator310 of the second peripheral area PA2 operates as the conductor 220 a.

The first substrate 100 is assembled with the second substrate 200 asshown in FIG. 5. The conductor 220 a of the second substrate 200, whichcovers the insulator 310, is aligned to be connected to the commonvoltage applying line 123 of the first substrate 100. The color filter230 of the second substrate 200 is aligned with the pixel electrode 129of the first substrate 100. To assemble the first and second substrates100 and 200 with each other, the sealing member 410 is formed at theboundary between the first peripheral area PA1 and first display areaDA1 of the first substrate 100 or at a boundary between the secondperipheral area PA2 and second display area DA2 of the second substrate200. Then, the liquid crystal 400 is injected between the first andsecond substrates 100 and 200 after or before assembling the first andsecond substrates 100 and 200 with each other.

As shown in FIG. 2, a driving module is assembled with the gate and databus lines 121 and 122 after injecting the liquid crystal 400 between thefirst and second substrates 100 and 200, thereby forming the LCDapparatus 600.

According to this exemplary embodiment of the invention, the insulator310 and conductor 220 a are formed at the second peripheral area PA2 ofthe second substrate 200 at the same time the color filter 230 is formedat the second display area PA2 of the second substrate 200 to apply thecommon voltage applied to the first substrate to the common electrode220 through the conductor 220 a.

FIG. 14 is a cross-sectional view of an LCD according to anotherexemplary embodiment of the present invention. In FIG. 14, the samereference numerals denote the same elements in FIGS. 2 to 13, and thusthe detailed descriptions of the same elements will be omitted.

Referring to FIG. 14, a transparent planarizing layer 272 is formed overa second transparent substrate 210 of the second substrate 200 toimprove step coverage of a color filter 230 formed at a second substrate200. A portion of the planarizing layer 272 that covers an insulator 310formed at a second peripheral area PA2 is removed by a photolithographyprocess.

According to the present exemplary embodiment of the invention, theinsulator 310 and conductor 220 a are formed at the second peripheralarea PA2 of the second substrate 200 and the color filter 230 is formedat the second display area PA2 of the second substrate 200 to providethe common voltage applied to the first substrate to the commonelectrode 220 through the conductor 220 a. Thus, the manufacturingprocesses for the LCD apparatus 600 is simplified and the LCD apparatus600 may be manufactured at a lower cost since the LCD apparatus does notuse a gold (Au) spacer. Also, the step coverage of the color filter 230and the common electrode 220 of the LCD apparatus 600 is improved.

FIG. 15 is a cross-sectional view of an LCD according to anotherexemplary embodiment of the present invention. In FIG. 15, the samereference numerals denote the same elements in FIGS. 2 to 13, and thusthe detailed descriptions of the same elements will be omitted.

Referring to FIG. 15, a transparent planarizing layer 272 is formed overa second transparent substrate 210 of the second substrate 200 toimprove step coverage of a color filter 230 formed at a second substrate200. When the combined thickness of a conductor 220 a and an insulator310 is smaller than a cell gap between the first and second substrates100 and 200, the planarizing layer 272 may be formed over the colorfilter 230 and insulator 310. In this exemplary embodiment of theinvention, the planarizing layer 272 is formed between the conductor 220a and insulator 310, so that the conductor 220 a may electricallyconnect a common voltage applying line 123 of the first substrate 100 tothe common electrode 220 of the second substrate 200.

According to this exemplary embodiment of the invention, the insulator310 and conductor 220 a are formed at the second peripheral area PA2 ofthe second substrate 200 and the color filter 230 is formed at thesecond display area PA2 of the second substrate 200 to provide thecommon voltage applied to the first substrate to the common electrode220 through the conductor 220 a. Thus, the manufacturing processes forthe LCD apparatus 600 is simplified and the LCD apparatus 600 may bemanufactured at a lower cost since the LCD apparatus does not use a gold(Au) spacer. Also, the step coverage of the color filter 230 and commonelectrode 220 of the LCD apparatus 600 is improved. Furthermore, theplanarizing layer 272 is formed between the conductor 220 a andinsulator 310, thereby electrically connecting the common voltageapplying line 123 of the first substrate 100 to the common electrode 220of the second substrate 200.

FIG. 16 is a cross-sectional view of an LCD apparatus according toanother exemplary embodiment of the present invention.

Referring to FIG. 16, an LCD apparatus 600 includes a first substrate100, a second substrate 200, a power-applying member 300 and liquidcrystal 400.

The first substrate 100 includes a first transparent substrate 110having a first display area DA1 and a first peripheral area PA1surrounding the first display area DA1, a plurality of pixels 120, acolor filter 160 and the power-applying member 300.

The pixels 120 and color filter 160 are placed in the first display areaDA1, and the power-applying member 300 is placed in the first peripheralarea PA1.

Referring to FIGS. 2, 3 and 16, the pixels 120 are arranged in the firstdisplay area DA1 in a matrix configuration. For example, when the LCDapparatus 600 has a resolution of 1024×768, 1024×768×3 units of thepixels 120 are formed on the first transparent substrate 110.

Each of the pixels 120 includes a gate bus line 121, a data bus line122, a thin film transistor (TFT) 128 and a pixel electrode 129.

The gate bus line 121 is extended in a first direction D1 from the firstperipheral area PA1 through the first display area DA1. If the LCDapparatus 600 has a resolution of 1024×768, 768 gate bus lines 121 areformed on the first transparent substrate 110. The 768 gate bus lines121 are divided into three groups and disposed in the first peripheralarea PA1, and each of the three groups forms a gate bus line channel 121a. Thus, three gate bus line channels 121 a are formed in the firstperipheral area PA1. Each of the gate bus line channels 121 a isconnected to a gate TCP to which a driving signal is applied.

The data bus line 122 is insulated from the gate bus line 121 andextended in a second direction D2 substantially perpendicular to thefirst direction D1. The data bus line 122 is extended from the firstperipheral area PA1 to the first display area DA1. If the LCD apparatus600 has a resolution of 1024×768, 1024×3 units of data bus lines 122 areformed on the first transparent substrate 110. The 1024×3 units of databus lines 122 are divided into twelve groups and disposed at the firstperipheral area PA1, and each of the twelve groups form a data bus linechannel 122 a. Thus, twelve data bus line channels 122 a are formed inthe first peripheral area PA1. Each of the data bus line channels 122 ais connected to a data TCP to which a driving signal is applied.

As shown in FIG. 3, the TFT 128 includes a gate electrode G, a sourceelectrode S, a drain electrode D and a channel layer C. The gate andsource electrodes G and S are extended from the gate and data bus lines121 and 122, respectively. The channel layer C is insulated from thegate electrode G and disposed on the gate electrode G. When a voltage isapplied to the gate electrode G, the channel layer C operates as aconductor. When the voltage is not applied to the gate electrode G, thechannel layer C operates as an insulator. The source and drainelectrodes S and D are electrically insulated from the channel layer andconnected to the channel layer C.

A common voltage applying line 123 is formed at a position adjacent tothe data bus line channel 122 a of the first peripheral area PA1 of thefirst substrate 100. The common voltage applying line 123 receives thecommon voltage externally provided through the first peripheral area PA1of the first substrate 100. A plurality of common voltage applying linesis formed at the first peripheral area PA1 to apply the common voltagehaving a uniform level to the common electrode 220 shown in FIG. 5.

The color filter 160 is disposed in the first display area DA1 of thefirst transparent substrate 110 in a matrix configuration, therebycovering the TFT 128. The color filter 160 includes a red color filter162, a green color filter 164 and a blue color filter 166. Two colorfilters adjacent to each other among the red, green and blue colorfilters 162, 164 and 166 overlap at edges thereof. Also, each of thered, green and blue color filters 162, 164 and 166 includes a contacthole so as to partially expose the drain electrode D.

The pixel electrode 129 is formed on the red, green and blue colorfilters 162, 164 and 166. The pixel electrode 129 is connected to thedrain electrode D of the TFT 128 through the contact hole. The pixelelectrode 129 is made of a transparent conductive material, such as, forexample, ITO or IZO.

When the pixel electrode 129 is formed on the color filter 160, thepixel electrode 129 may be placed at a position more distantly spacedfrom the gate and data bus lines 121 and 122. Thus, the LCD apparatus600 may prevent a parasitic capacitance between the pixel electrode 129and the gate and data bus lines 121 and 122, which in turn preventsdeterioration of an image caused by distortion of the driving signal.Also, since the red, green and blue color filters 162, 164 and 166 arepartially overlapped, the LCD apparatus 600 does not need a blackmatrix, thereby increasing an area through which light is transmitted.

The power-applying member 300 includes an insulator 310 and a conductor129 a.

The insulator 310 is formed in the first peripheral area PA1 of thefirst substrate 100. The insulator 310 is formed at a position adjacentto the common voltage applying line 123 formed in the first peripheralarea PA1 of the first substrate 100. In this exemplary embodiment of theinvention, the insulator 310 is formed using a portion of a color filterlayer that also forms the color filter 160. The color filter layerincludes a red color filter layer 162 a, a green color filter layer 164a and a blue color filter layer 166 a. The red, green and blue colorfilter layers 162 a, 164 a and 166 a formed in the first peripheral areaPA1 are formed at the same time the color filter 160 is formed in thefirst display area DA1.

Particularly, the red color filter layer 162 a is formed at the sametime the red color filter 162 is formed in the first display area DA1.The green color filter layer 164 a is formed on the red color filterlayer 162 a at the same time the green color filter 164 is formed in thefirst display area DA1. The blue color filter layer 166 a is formed onthe green color filter layer 164 a at the same time the blue colorfilter 166 is formed in the first display area DA1.

The insulator 310 having the red, green and blue color filter layers 162a, 164 a and 166 a has a thickness substantially equal to a distancebetween the first and second substrates 100 and 200.

The conductor 129 a covers the insulator 310 formed in the firstperipheral area PA1 and is insulated from the pixel electrode 129 formedat the first display area DA1. The conductor 129 a comprises atransparent conductive material, such as, for example, ITO or IZO. Theconductor 129 a may be simultaneously formed with the pixel electrode129.

Referring to FIG. 16, the second substrate 200 includes a secondtransparent substrate 210 and a common electrode 220. The secondtransparent substrate 200 may further include a black matrix 240.

The second transparent substrate 210 faces the first transparentsubstrate 110 and includes a second display area DA2 and a secondperipheral area PA2 surrounding the second display area DA2. The seconddisplay area DA2 and second peripheral area PA2 face the first displayarea DA1 and first peripheral area PA1 of the first substrate 100,respectively. The common electrode 220 is formed in the second displayarea DA2 and partially extends into the second peripheral area PA2. Theextended portion of the common electrode 220 is connected to theconductor 129 a of the power-applying member 300 placed in the firstperipheral area PA1 of the first substrate 100.

The black matrix 240 having a lattice-shape is formed between the secondtransparent substrate 210 and common electrode 220 to block light fromleaking between the pixel electrode 219 and an adjacent pixel electrode.The black matrix 240 is made of, for example, a chromium layer, adouble-layer having a chromium layer and a chromium oxide layer, or ablack organic layer having a light transmittance substantially equal tothat of chromium Cr.

A sealing member 410 having a band shape is formed at a boundary betweenthe first peripheral area PA1 and first display area DA1 of the firstsubstrate 100 or at a boundary between the second peripheral area PA2and second display area DA2 of the second substrate 200. The liquidcrystal 400 is dropped into the first display area DA1 or second displayarea DA2 surrounded by the sealing member 410, and then the firstsubstrate 100 is assembled with the second substrate 200. Alternatively,the liquid crystal 400 may be injected between the first and secondsubstrates 100 and 200 after the first and second substrates 100 and 200are assembled with each other using the sealing member 410. Theconductor 129 a of the first substrate 100 makes contact with the commonelectrode 220 of the second substrate 200 after the first substrate 100and the second substrate 200 are assembled together.

According to this exemplary embodiment of the invention, the insulator310 and conductor 129 a are formed in the first peripheral area PA1 ofthe first substrate 100 and the color filter 160 is formed in the firstdisplay area DA1 of the first substrate 100 to provide the commonvoltage applied to the first substrate to the common electrode 220through the conductor 129 a. Thus, the manufacturing processes for theLCD apparatus 600 may be simplified. Also, since the LCD apparatus 600does not use a gold (Au) spacer, the LCD apparatus 600 may bemanufactured at a lower cost.

FIG. 17 is a cross-sectional view of an LCD apparatus according toanother exemplary embodiment of the present invention. In FIG. 17, thesame reference numerals denote the same elements in FIG. 16, and thusthe detailed descriptions of the same elements will be omitted.

Referring to FIG. 17, a transparent planarizing layer 172 is formed overa first transparent substrate 110 of the first substrate 100 to improvestep coverage of a color filter 160 formed at a first substrate 100. Aportion of the planarizing layer 172 that covers an insulator 310 formedin a first peripheral area PA1 is removed by a photolithography process.Thus, a distance between a pixel electrode 129 and a gate bus line 121and between the pixel electrode 129 and a data bus line 122 of the LCDapparatus is increased, thereby improving display quality of an image.

According to this exemplary embodiment of the invention, the insulator310 and the conductor 129 a are formed in the first peripheral area PA1of the first substrate 100 and the color filter 160 is formed in thefirst display area DA1 of the first substrate 100 to provide the commonvoltage applied to the first substrate 100 to the common electrode 220of the second substrate 200 through the conductor 129 a. Thus, themanufacturing processes for the LCD apparatus 600 is simplified and theLCD apparatus 600 may be manufactured at a lower cost since the LCDapparatus 600 does not use a gold (Au) spacer. Also, the color filter160 and the common electrode 220 of the LCD apparatus 600 have improvedstep coverage.

FIG. 18 is a cross-sectional view of an LCD apparatus according toanother exemplary embodiment of the present invention. In FIG. 18, thesame reference numerals denote the same elements in FIG. 16, and thusthe detailed descriptions of the same elements will be omitted.

Referring to FIG. 18, a transparent planarizing layer 174 is formed overa first transparent substrate 110 of the first substrate 100 to improvestep coverage of a color filter 160 formed at a first substrate 100. Ifthe total thickness of a conductor 129 a and an insulator 310 is smallerthan a cell gap between the first and second substrates 100 and 200, theplanarizing layer 174 may be formed over the color filter 160 and theinsulator 310. In this exemplary embodiment of the invention, theplanarizing layer 174 is formed between the color filter 160 and thepixel electrode 129, so that the conductor 129 a is electricallyconnected to a common electrode 220 of the second substrate 200.

According to this exemplary embodiment of the invention, the insulator310 and the conductor 129 a are formed in the first peripheral area PA1of the first substrate 100 and the color filter 160 is formed in thefirst display area DA1 of the first substrate 100 to provide the commonvoltage applied to the first substrate 100 to the common electrode 220of the second substrate 200 through the conductor 129 a. Thus, themanufacturing processes for the LCD apparatus 600 is simplified and theLCD apparatus 600 may be manufactured at a lower cost since the LCDapparatus does not use a gold (Au) spacer. Also, the color filter 160and the common electrode 220 of the LCD apparatus 600 have improved stepcoverage. Furthermore, the planarizing layer 174 is formed between thecolor filter 160 and the pixel electrode 129 and between the insulator310 and conductor 129 a, thereby electrically connecting the conductor129 a formed in the first peripheral area PA1 of the first substrate 100to the common electrode 220 of the second substrate 200.

FIG. 19 is a cross-sectional view of an LCD apparatus according toanother exemplary embodiment of the present invention. In FIG. 19, thesame reference numerals denote the same elements in FIG. 16, and thusthe detailed descriptions of the same elements will be omitted.

Referring to FIG. 19, a common electrode 220 is formed between a secondtransparent substrate 210 and a black matrix 240. This structureprevents deterioration of display quality of an image due to an electricfield caused by bad step coverage of the common electrode 220 formed onthe black matrix 240. The black matrix 240 has an opening 244 formed ata position corresponding to a conductor 129 a wrapping an insulator 310.The conductor 129 a makes contact with the common electrode 220 throughthe opening 244 formed in the black matrix 240.

According to this exemplary embodiment of the invention, the insulator310 and the conductor 129 a are formed in the first peripheral area PA1of the first substrate 100 and the color filter 160 is formed in thefirst display area DA1 of the first substrate 100 to provide the commonvoltage applied to the first substrate 100 to the common electrode 220of the second substrate 200 through the conductor 129 a. Thus, themanufacturing processes for the LCD apparatus 600 is simplified and theLCD apparatus 600 may be manufactured at a lower cost since the LCDapparatus does not use a gold (Au) spacer. Also, the LCD apparatus 600may prevent deterioration of the display quality of the image due to theelectric field caused by the black matrix 240.

FIG. 20 is a cross-sectional view of an LCD apparatus according toanother exemplary embodiment of the present invention. In FIG. 20, thesame reference numerals denote the same elements in FIG. 16, and thusthe detailed descriptions of the same elements will be omitted.

Referring to FIG. 20, a conductor 129 a formed in a first peripheralarea PA1 of a first substrate 100 includes a first concavo-convexportion 129 b that makes contact with a common electrode 220 formed in asecond peripheral area PA2 of a second substrate 200. The commonelectrode 220 includes a second concavo-convex portion 220 b that makescontact with the conductor 129 a. The first concavo-convex portion 129 bis formed by a slit-exposure method at the same time a color filter 160is formed, and the second concavo-convex portion 220 b is formed by aslit-exposure method at the same time a black matrix 240 is patterned.

Although the total thickness of the conductor 129 a and an insulator 310is different from a distance between the first and second substrates 100and 200, the conductor 129 a may make contact with the common electrode220 by the first and second concavo-convex portions 129 b and 220 b,thereby applying a common voltage applied to the first substrate to thecommon electrode 220 of the second substrate 200.

According to this exemplary embodiment of the invention, the insulator310 and the conductor 129 a are formed in the first peripheral area PA1of the first substrate 100 and the color filter 160 is formed in thefirst display area DA1 of the first substrate 100 to provide the commonvoltage applied to the first substrate 100 to the common electrode 220of the second substrate 200 through the conductor 129 a. Thus, themanufacturing processes for the LCD apparatus 600 is simplified and theLCD apparatus 600 may be manufactured at a lower cost since the LCDapparatus does not use a gold (Au) spacer. Also, although the totalthickness of the conductor 129 a and insulator 310 is different from thedistance between the first and second substrates 100 and 200, theconductor 129 a may make contact with the common electrode 220.

FIG. 21 is a cross-sectional view of an LCD apparatus according toanother exemplary embodiment of the present invention. In FIG. 21, thesame reference numerals denote the same elements in FIG. 16, and thusthe detailed descriptions of the same elements will be omitted.

Referring to FIG. 21, a spacer 192 having a pole shape is formed in afirst display area DA1 of a first substrate 100 or in a second displayarea DA2 of a second substrate 200. In this exemplary embodiment of theinvention, the spacer 192 is formed in the first display area DA1 of thefirst substrate 100. The spacer 192 is formed between a pixel electrode129 and an adjacent pixel electrode to maintain a cell gap between thefirst and second substrates 100 and 200.

An insulator 300 is formed in a first peripheral area PA1 of the firstsubstrate 100 and in a second peripheral area PA2 of the secondsubstrate 200. The insulator 300 is formed at the same time the spacer192 is formed at the first and second display areas DA1 and DA2. Aconductor 129 a is formed on the insulator 300 so as to apply a commonvoltage applied to the first substrate 100 to a common electrode 220 ofthe second substrate 200.

According to this exemplary embodiment of the invention, the spacer 192for maintaining the cell gap between the first and second substrates 100and 200 is used as an insulator while the first and second substrates100 and 200 are manufactured. The conductor 129 a formed on theinsulator 300 applies the common voltage applied to the first substrate100 to the common electrode 220 of the second substrate 200. Thus, themanufacturing processes for the LCD apparatus 600 is simplified and theLCD apparatus 600 may be manufactured at a lower cost since the LCDapparatus does not use a gold (Au) spacer.

In various exemplary embodiments of the present invention, the commonvoltage applied to the first substrate is applied to the commonelectrode of the second substrate using an insulator formed bypatterning the color filter layer and a conductor formed on theinsulator. The common voltage applied to the first substrate may also beprovided to the common electrode of the second substrate using a spacerformed by patterning the color filter layer.

While the present invention has been described in detail with referenceto the preferred embodiments, it is to be understood that the inventionis not limited to the disclosed embodiments, but, on the contrary, isintended to cover various modifications and equivalent arrangementsincluded within the sprit and scope of the appended claims.

1. A liquid crystal display device, comprising: a first substrate; acommon electrode formed over the first substrate; a second substratedisposed opposite the first substrate; a plurality of pixel electrodesformed over the second substrate; a common voltage applying member thatapplies a common voltage to the common electrode and that maintains acell gap between the first substrate and the second substrate, thecommon voltage-applying member comprising an insulator and a conductorformed over the insulator; a color filter formed over the secondsubstrate; and a black matrix formed over the first substrate, wherein:the common voltage applying member is disposed between a firstperipheral area of the first substrate and a second peripheral area ofthe second substrate, the first and second peripheral areas beingoutside display areas of the first and second substrates, the conductoris insulated from the pixel electrodes, the plurality of pixelelectrodes are formed of the same material as the conductor, the colorfilter is formed of the same material as the insulator, the black matrixis formed over the common electrode, and the conductor contacts thecommon electrode through an opening in the black matrix.
 2. A liquidcrystal display device, comprising: a first substrate; a commonelectrode formed over the first substrate; a second substrate disposedopposite the first substrate; a plurality of pixel electrodes formedover the second substrate; a common voltage applying member that appliesa common voltage to the common electrode and that maintains a cell gapbetween the first substrate and the second substrate, the commonvoltage-applying member comprising an insulator and a conductor formedover the insulator; and a color filter formed over the second substrate,wherein: the common voltage applying member is disposed between a firstperipheral area of the first substrate and a second peripheral area ofthe second substrate, the first and second peripheral areas beingoutside display areas of the first and second substrates, the conductoris insulated from the pixel electrodes, the plurality of pixelelectrodes are formed of the same material as the conductor, the colorfilter is formed of the same material as the insulator, and aconcavo-convex portion of the conductor is in contact with acorresponding concavo-convex portion of the common electrode.
 3. Aliquid crystal display device, comprising: a first substrate; a commonelectrode formed on the first substrate; a second substrate disposedopposite the first substrate; a plurality of pixel electrodes formedover the second substrate; a common voltage applying member that appliesa common voltage to the common electrode and that maintains a cell gapbetween the first substrate and the second substrate, the commonvoltage-applying member comprising an insulator and a conductor formedover the insulator; and a black matrix formed on the common electrode,wherein: part of the conductor is sandwiched between the insulator andthe common electrode, the common voltage applying member is disposedoutside display areas of the first and second substrates, the conductoris insulated from the pixel electrodes, and the conductor contacts thecommon electrode through an opening in the black matrix.
 4. A liquidcrystal display device, comprising: a first substrate; a commonelectrode formed on the first substrate; a second substrate disposedopposite the first substrate; a plurality of pixel electrodes formedover the second substrate; and a common voltage applying member thatapplies a common voltage to the common electrode and that maintains acell gap between the first substrate and the second substrate, thecommon voltage-applying member comprising an insulator and a conductorformed over the insulator, wherein: part of the conductor is sandwichedbetween the insulator and the common electrode, the common voltageapplying member is disposed outside display areas of the first andsecond substrates, the conductor is insulated from the pixel electrodes,and a concavo-convex portion of the conductor is in contact with acorresponding concavo-convex portion of the common electrode.
 5. Aliquid crystal display device, comprising: a first substrate; a commonelectrode formed on the first substrate; a second substrate disposedopposite the first substrate; a common voltage applying member thatapplies a common voltage to the common electrode and that maintains acell gap between the first substrate and the second substrate, thecommon voltage-applying member comprising an insulator and a conductorformed over the insulator, wherein part of the conductor is sandwichedbetween the insulator and the common electrode; and a black matrixformed on the common electrode, wherein the conductor contacts thecommon electrode through an opening in the black matrix.